Losing only index of homepage doesn't mean a penalty. Don't stop your link building.
Adsense is about making side income from your site. Don't too much rely on it.
It's treated as a backlink, but it's hard to tell whether they are relevant backlinks due to difference of language.
I would avoid doing this. Such a risk.
If not for a penalty, your competitors might have been working harder than you to overtake your position.
It's not a problem. Just some help by google.
If we think about doing the right way, directory submission is better.
The domains are treated the same by google.
Backlinks is the way search engines recognize if your site is popular in the web.
Separate names with a comma.
